The performance improvement of electronic devices such as bipolar transistors and field-effect transistors has dramatically increased the operating speed of large-scale integrated circuits (LSI). However, although achieving performance improvement, the downsizing of transistors has encountered a serious problem with electrical interconnection therebetween in relation to the increase of interconnect resistance and capacitance between interconnects, which is becoming a bottleneck in the improvement of LSI performance.
In view of the foregoing problem with electrical interconnection, some proposals have been made for an optically interconnected LSI, which includes optically interconnected components. Optical interconnection has little frequency dependence of loss at frequencies from DC to 100 GHz or more, and the interconnect path suffers from no electromagnetic interference, allowing interconnection at several 10 Gbps or more to be easily realized.
This type of intra-LSI optical interconnection requires a high-speed light receiving device made of silicon (Si), which is a LSI substrate material. In general, because Si is an indirect transition semiconductor, it has low light absorption efficiency, and it is difficult to satisfy both of high light absorption efficiency and high speed. To solve this, a light receiving device of the focusing antenna type based on surface plasmons traveling on the surface of a metal or other conductive material is known (Japanese Journal of Applied Physics, 2005, Vol. 44, No. 12, p. L364). On the other hand, to improve the light transmission efficiency of a small opening, a technique of using an asymmetric opening Is known (JP-A 2001-189519 (Kokai)).